From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA1B6ECAAD5 for ; Sun, 28 Aug 2022 20:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229990AbiH1Url (ORCPT ); Sun, 28 Aug 2022 16:47:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiH1Uri (ORCPT ); Sun, 28 Aug 2022 16:47:38 -0400 Received: from mail-yw1-x112c.google.com (mail-yw1-x112c.google.com [IPv6:2607:f8b0:4864:20::112c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46FAF2B633 for ; Sun, 28 Aug 2022 13:47:37 -0700 (PDT) Received: by mail-yw1-x112c.google.com with SMTP id 00721157ae682-333a4a5d495so153289107b3.10 for ; Sun, 28 Aug 2022 13:47:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=konsulko.com; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=kAoFlc805AehyA9fyFd+VfhPEKAjCfCEmxXhiLGWNEA=; b=DCyGAi54ZQfZz1Pj3ySan2iv3FHNPjwl2y25Zod9yfXkzqjIl3X0JcpY4/kAPx/8Vo wqrWceX9ObCgJwXwdrrDww+q2wkwXT1CJRLPgyj7O0PyKnusSoKzuKv4X+p9ia+ip1Qs ZA5pxYh9vSHRz355bKMmHKQ7D/vfGdT9/W5Oo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=kAoFlc805AehyA9fyFd+VfhPEKAjCfCEmxXhiLGWNEA=; b=UXsmxUpTga4VXNfpMpPcTjvmzHpb+d4vzwEQd2UDdfxOxXaPiWyCLgBymMQD+5w7WT 1aWSM9rdryPZF444WDEjLhkedg42HkhwUrzJZ3RZcAiIAsLLBsPFKl2Pg20ZBlKVnB7m aMXcfKrLfmaZxk0Wie8BDzBCZlg4hJVyUPP6jlHZtTUPCIaG7iDycwxZcpODm/Yh4hHS OrsRF8kVas+7KXTX8DmbV6VsSckFKXBlXRGEOQ2bq9CqXcxh1rrlA17ObejHp7ssxrTX PW/lSMXW5Uw9lGmYznZvR4XUdZtVMMDTKC2E9iAT3o/TO6U+N9RbllA5x3NLYQ8Yqxw0 nmaA== X-Gm-Message-State: ACgBeo2jIP7xTRTTdrfrcNvrqqJhdj/vqo3j+54V6RmsSIgvKdORfqoE gtbwvETyYsA+t//ueS/TlAFApOzlLLq8+zRsmkQ0Aw== X-Google-Smtp-Source: AA6agR6iG18Lax5VtMCCCh65Zj+vVC32muhpzLTE4lF4tiDHLJwXwnRwPrJG3gEmf1sHIs7VY5gmShNrlDXdCoRWrcY= X-Received: by 2002:a81:6d85:0:b0:339:ace2:f30b with SMTP id i127-20020a816d85000000b00339ace2f30bmr7412005ywc.328.1661719656472; Sun, 28 Aug 2022 13:47:36 -0700 (PDT) MIME-Version: 1.0 References: <20220827104600.1813214-1-liushixin2@huawei.com> <20220827104600.1813214-3-liushixin2@huawei.com> In-Reply-To: <20220827104600.1813214-3-liushixin2@huawei.com> From: Vitaly Wool Date: Sun, 28 Aug 2022 22:47:25 +0200 Message-ID: Subject: Re: [PATCH -next v3 2/5] frontswap: invoke ops->init for online swap device in frontswap_register_ops To: Liu Shixin Cc: Seth Jennings , Dan Streetman , Andrew Morton , Nathan Chancellor , Christoph Hellwig , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kefeng Wang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 27, 2022 at 12:12 PM Liu Shixin wrote: > > Since we are supported to delay zswap initializaton, we need to invoke > ops->init for the swap device which is already online when register > backend. > > This patch is a revert of f328c1d16e4c ("frontswap: simplify frontswap_register_ops") > and 633423a09cb5 ("mm: mark swap_lock and swap_active_head static") > > Signed-off-by: Liu Shixin Sorry, is this the revert of 2 patches at the same time? I would rather not do it like that. Thanks, Vitaly > --- > include/linux/swapfile.h | 2 ++ > mm/frontswap.c | 47 ++++++++++++++++++++++++++++++++++++++++ > mm/swapfile.c | 4 ++-- > 3 files changed, 51 insertions(+), 2 deletions(-) > > diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h > index 2fbcc9afd814..75fc069594a5 100644 > --- a/include/linux/swapfile.h > +++ b/include/linux/swapfile.h > @@ -6,6 +6,8 @@ > * these were static in swapfile.c but frontswap.c needs them and we don't > * want to expose them to the dozens of source files that include swap.h > */ > +extern spinlock_t swap_lock; > +extern struct plist_head swap_active_head; > extern struct swap_info_struct *swap_info[]; > extern unsigned long generic_max_swapfile_size(void); > /* Maximum swapfile size supported for the arch (not inclusive). */ > diff --git a/mm/frontswap.c b/mm/frontswap.c > index 620f95af81dd..449e6f499b88 100644 > --- a/mm/frontswap.c > +++ b/mm/frontswap.c > @@ -96,11 +96,58 @@ static inline void inc_frontswap_invalidates(void) { } > */ > int frontswap_register_ops(const struct frontswap_ops *ops) > { > + DECLARE_BITMAP(a, MAX_SWAPFILES); > + DECLARE_BITMAP(b, MAX_SWAPFILES); > + struct swap_info_struct *si; > + unsigned int i; > + > if (frontswap_ops) > return -EINVAL; > > + bitmap_zero(a, MAX_SWAPFILES); > + bitmap_zero(b, MAX_SWAPFILES); > + > + spin_lock(&swap_lock); > + plist_for_each_entry(si, &swap_active_head, list) { > + if (!WARN_ON(!si->frontswap_map)) > + __set_bit(si->type, a); > + } > + spin_unlock(&swap_lock); > + > + /* the new ops needs to know the currently active swap devices */ > + for_each_set_bit(i, a, MAX_SWAPFILES) { > + pr_err("init frontswap_ops\n"); > + ops->init(i); > + } > + > frontswap_ops = ops; > static_branch_inc(&frontswap_enabled_key); > + > + spin_lock(&swap_lock); > + plist_for_each_entry(si, &swap_active_head, list) { > + if (si->frontswap_map) > + __set_bit(si->type, b); > + } > + spin_unlock(&swap_lock); > + > + /* > + * On the very unlikely chance that a swap device was added or > + * removed between setting the "a" list bits and the ops init > + * calls, we re-check and do init or invalidate for any changed > + * bits. > + */ > + if (unlikely(!bitmap_equal(a, b, MAX_SWAPFILES))) { > + for (i = 0; i < MAX_SWAPFILES; i++) { > + if (!test_bit(i, a) && test_bit(i, b)) { > + pr_err("init frontswap_ops re\n"); > + ops->init(i); > + } else if (test_bit(i, a) && !test_bit(i, b)) { > + pr_err("inval frontswap_ops re\n"); > + ops->invalidate_area(i); > + } > + } > + } > + > return 0; > } > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 469d9af86be2..d383b282f269 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -51,7 +51,7 @@ static bool swap_count_continued(struct swap_info_struct *, pgoff_t, > unsigned char); > static void free_swap_count_continuations(struct swap_info_struct *); > > -static DEFINE_SPINLOCK(swap_lock); > +DEFINE_SPINLOCK(swap_lock); > static unsigned int nr_swapfiles; > atomic_long_t nr_swap_pages; > /* > @@ -77,7 +77,7 @@ static const char Unused_offset[] = "Unused swap offset entry "; > * all active swap_info_structs > * protected with swap_lock, and ordered by priority. > */ > -static PLIST_HEAD(swap_active_head); > +PLIST_HEAD(swap_active_head); > > /* > * all available (active, not full) swap_info_structs > -- > 2.25.1 >